4 ms·

Plugging the site I just created that shows current (live) starlink coverage: https://droid.cafe/starlink https://droid.cafe/starlink As a Canadian I'm pretty

by gpm 6y ago

Plugging the site I just created that shows current (live) starlink coverage: https://droid.cafe/starlink https://droid.cafe/starlink As a Canadian I'm pretty excited about the potential for good internet outside of the cities and well beaten paths.

cartooncutout 6y ago
degrees from horizon?
- gpm 6y ago
  Imagine you're standing in a flat field, facing the satellite. Degrees from the horizon is how far you would have to bend your neck to be looking straight at the satellite. FCC filings suggest 25 is the absolute minimum for service, the final constellation is likely to use somewhere in 40-60 as the actual limit. I've received this question a few times now, anyone have a better name? Or maybe I should just add a ? button with a diagram?
  - cartooncutout 6y ago
    thanks for the elaboration.. maybe just add this explanation as a tooltip on hover or something similar?
  - tialaramex 6y ago
    I'm guessing based on my own experience that it's obvious if you understand why that would matter. So the diagram may be the best option, maybe with a Wikipedia link if there's an appropriate one?
  - toomuchtodo 6y ago
    You might link to the graphic on this page as a quick reference. Should be public domain as a government work if you want to host it. https://spotthestation.nasa.gov/message_example.cfm https://spotthestation.nasa.gov/message_example.cfm https://spotthestation.nasa.gov/images/astro_horizon.png https://spotthestation.nasa.gov/images/astro_horizon.png
  - samcheng 6y ago
    A common term is zenith angle, although that's the complement of the angle you're describing.
- deleted 6y ago
  [deleted]
- tialaramex 6y ago
  The planet is definitely in the way of radio transmissions between you and a satellite "below the horizon" and even if it could pass through the planet that's a long way. On the other hand a satellite in a boring orbit that's directly above you is 90° from the horizon with no obstacles and as close as it'll ever be so your reception ought to be good. An optimist might believe Starlink will work at 10° above the horizon. A pessimist might doubt anybody will get it working below 80° (ie almost directly overhead). The reality is likely to be in between and this UI lets you see the effect.
  - JshWright 6y ago
    "Optimism" and "pessimism" don't really apply here. While SpaceX hasn't publicly committed to what the "operational" value will be, it's likely they had a very good idea before they flew any hardware.
    - gpm 6y ago
      SpaceX is still developing the user terminal, there might be a bit of optimism/pessimism in the degree to which they'll be able to make the user terminal target different angles (without bloating costs), though the person you're replying to definitely exaggerated the extent.
RspecMAuthortah 6y ago
How did you track the locations of the satellites live?
- toomuchtodo 6y ago
  > NORAD maintains general perturbation element sets on all resident space objects. These element sets are periodically refined so as to maintain a reasonable prediction capability on all space objects. In turn, these element sets are provided to users. The purpose of this report is to provide the user with a means of propagating these element sets in time to obtain a position and velocity of the space object. [1] For the curious, here is the wikipedia page [2] with details on the US Space Surveillance Network used to obtain this data (30+ ground-based radars and optical telescopes worldwide, plus 6 satellites in orbit). [1] https://www.celestrak.com/NORAD/elements/supplemental/ https://www.celestrak.com/NORAD/elements/supplemental/ (didn't link directly to the starlink txt file on purpose, link for reference only, please don't hug the site to death) [2] https://en.wikipedia.org/wiki/United_States_Space_Surveillance_Network https://en.wikipedia.org/wiki/United_States_Space_Surveillan...
  - gpm 6y ago
    Exactly this. I grabbed a set of TLEs from celestrak (which I'm serving from my site), and then I propagate them forward with satellite-js [1] to the current date 6 times a second. [1] https://github.com/shashwatak/satellite-js https://github.com/shashwatak/satellite-js
blacksmith_tb 6y ago
Very cool visualization, but am I seeing correctly that Starlink only covers the southern half of Canada? I guess that would still mean a lot of potential users, but also most of the major cities, which are already wired up?
- holyDictionary 6y ago
  I'm not completely sure but I believe that area has at least 97% of the population of Canada.
  - holyDictionary 6y ago
    There's a slider to choose the area of the circle of each satellite, so maybe mine are just way too big.
- gpm 6y ago
  This is true, but practically no one lives in the northern half so no one cares. There's also a second stage that will cover the poles (they're required by the us government to get Alaska iirc), so eventually it will cover all of it.
  - Reason077 6y ago
    > "practically no one lives in the northern half so no one cares." I have friends who live in Iqaluit, Nunavut. It's a nice place to live with a cool community, but everything there is very expensive, including internet service. How about $399/month for 5 Mbps service, capped at 55 GB? And that's with the resident's discount! If Starlink were available here it would be an absolute game changer. https://www.qiniq.com/internet/ https://www.qiniq.com/internet/
    - gpm 6y ago
      Ya, but it's like them and one other family :p Seriously though, the population of Nunavut is roughly 40k. I guess that 90% of them are potential customers so maybe I shouldn't dismiss them too early, but you can see why I think SpaceX is right to consider them (and the other northern areas) lower priority.
ciarannolan 6y ago
Aren't the sats flying across space? Why do they appear stationary in this visualization?
- bergeyboy 6y ago
  In the animation, they are moving so slowly they appear to be stationary. Try lining one up with your cursor.
  - ciarannolan 6y ago
    Ah, okay. But there are stripes over specific areas of interest, like Canada and Africa. Maybe it's just coincidence that I looked at it when they were there?
    - gpm 6y ago
      The really dense strips would be coincidence (those are from recent launches, the satellites in them are slowly spreading apart until they look like all the other satellites). There is always a generally high concentration of satellites at the northern and southern end of the range as a result of orbital mechanics though.
      - ciarannolan 6y ago
        Cool, thanks! Very neat tool.

by gpm 6y ago

cartooncutout 6y ago

degrees from horizon?

gpm 6y ago
Imagine you're standing in a flat field, facing the satellite. Degrees from the horizon is how far you would have to bend your neck to be looking straight at the satellite. FCC filings suggest 25 is the absolute minimum for service, the final constellation is likely to use somewhere in 40-60 as the actual limit. I've received this question a few times now, anyone have a better name? Or maybe I should just add a ? button with a diagram?
- cartooncutout 6y ago
  thanks for the elaboration.. maybe just add this explanation as a tooltip on hover or something similar?
- tialaramex 6y ago
  I'm guessing based on my own experience that it's obvious if you understand why that would matter. So the diagram may be the best option, maybe with a Wikipedia link if there's an appropriate one?
- toomuchtodo 6y ago
  You might link to the graphic on this page as a quick reference. Should be public domain as a government work if you want to host it. https://spotthestation.nasa.gov/message_example.cfm https://spotthestation.nasa.gov/message_example.cfm https://spotthestation.nasa.gov/images/astro_horizon.png https://spotthestation.nasa.gov/images/astro_horizon.png
- samcheng 6y ago
  A common term is zenith angle, although that's the complement of the angle you're describing.
deleted 6y ago
[deleted]
tialaramex 6y ago
The planet is definitely in the way of radio transmissions between you and a satellite "below the horizon" and even if it could pass through the planet that's a long way. On the other hand a satellite in a boring orbit that's directly above you is 90° from the horizon with no obstacles and as close as it'll ever be so your reception ought to be good. An optimist might believe Starlink will work at 10° above the horizon. A pessimist might doubt anybody will get it working below 80° (ie almost directly overhead). The reality is likely to be in between and this UI lets you see the effect.
- JshWright 6y ago
  "Optimism" and "pessimism" don't really apply here. While SpaceX hasn't publicly committed to what the "operational" value will be, it's likely they had a very good idea before they flew any hardware.
  - gpm 6y ago
    SpaceX is still developing the user terminal, there might be a bit of optimism/pessimism in the degree to which they'll be able to make the user terminal target different angles (without bloating costs), though the person you're replying to definitely exaggerated the extent.

RspecMAuthortah 6y ago

How did you track the locations of the satellites live?

toomuchtodo 6y ago
> NORAD maintains general perturbation element sets on all resident space objects. These element sets are periodically refined so as to maintain a reasonable prediction capability on all space objects. In turn, these element sets are provided to users. The purpose of this report is to provide the user with a means of propagating these element sets in time to obtain a position and velocity of the space object. [1] For the curious, here is the wikipedia page [2] with details on the US Space Surveillance Network used to obtain this data (30+ ground-based radars and optical telescopes worldwide, plus 6 satellites in orbit). [1] https://www.celestrak.com/NORAD/elements/supplemental/ https://www.celestrak.com/NORAD/elements/supplemental/ (didn't link directly to the starlink txt file on purpose, link for reference only, please don't hug the site to death) [2] https://en.wikipedia.org/wiki/United_States_Space_Surveillance_Network https://en.wikipedia.org/wiki/United_States_Space_Surveillan...
- gpm 6y ago
  Exactly this. I grabbed a set of TLEs from celestrak (which I'm serving from my site), and then I propagate them forward with satellite-js [1] to the current date 6 times a second. [1] https://github.com/shashwatak/satellite-js https://github.com/shashwatak/satellite-js

blacksmith_tb 6y ago

Very cool visualization, but am I seeing correctly that Starlink only covers the southern half of Canada? I guess that would still mean a lot of potential users, but also most of the major cities, which are already wired up?

holyDictionary 6y ago
I'm not completely sure but I believe that area has at least 97% of the population of Canada.
- holyDictionary 6y ago
  There's a slider to choose the area of the circle of each satellite, so maybe mine are just way too big.
gpm 6y ago
This is true, but practically no one lives in the northern half so no one cares. There's also a second stage that will cover the poles (they're required by the us government to get Alaska iirc), so eventually it will cover all of it.
- Reason077 6y ago
  > "practically no one lives in the northern half so no one cares." I have friends who live in Iqaluit, Nunavut. It's a nice place to live with a cool community, but everything there is very expensive, including internet service. How about $399/month for 5 Mbps service, capped at 55 GB? And that's with the resident's discount! If Starlink were available here it would be an absolute game changer. https://www.qiniq.com/internet/ https://www.qiniq.com/internet/
  - gpm 6y ago
    Ya, but it's like them and one other family :p Seriously though, the population of Nunavut is roughly 40k. I guess that 90% of them are potential customers so maybe I shouldn't dismiss them too early, but you can see why I think SpaceX is right to consider them (and the other northern areas) lower priority.

ciarannolan 6y ago

Aren't the sats flying across space? Why do they appear stationary in this visualization?

bergeyboy 6y ago
In the animation, they are moving so slowly they appear to be stationary. Try lining one up with your cursor.
- ciarannolan 6y ago
  Ah, okay. But there are stripes over specific areas of interest, like Canada and Africa. Maybe it's just coincidence that I looked at it when they were there?
  - gpm 6y ago
    The really dense strips would be coincidence (those are from recent launches, the satellites in them are slowly spreading apart until they look like all the other satellites). There is always a generally high concentration of satellites at the northern and southern end of the range as a result of orbital mechanics though.
    - ciarannolan 6y ago
      Cool, thanks! Very neat tool.